Pre-existing hypertension w pre-eclampsia, first trimester

This code signifies a pregnancy complicated by the presence of pre-existing hypertension that has progressed to pre-eclampsia, specifically when diagnosed during the first trimester. Pre-existing hypertension refers to chronic hypertension present before pregnancy or diagnosed before 20 weeks' gestation. Pre-eclampsia is a multisystem disorder characterized by new-onset hypertension and proteinuria after 20 weeks' gestation, but in this context, it is superimposed on pre-existing hypertension.

Apply this code when documentation clearly indicates a pregnant patient with a history of chronic hypertension who develops signs and symptoms of pre-eclampsia (e.g., new-onset proteinuria, worsening hypertension, or other organ dysfunction) during the first trimester of pregnancy. Supporting documentation would include physician notes detailing the pre-existing hypertension, the diagnosis of superimposed pre-eclampsia, and the gestational age at the time of diagnosis.

• Always sequence this code as the principal diagnosis when it is the primary reason for the encounter.
• Do not confuse this with gestational hypertension or pre-eclampsia without pre-existing hypertension.
• Ensure the medical record explicitly states both "pre-existing hypertension" and "pre-eclampsia" and the "first trimester" for accurate code assignment.